Sharpening and filing apparatus for serrated cutting edges



W. F. JUST SHARPENING AND FILING APPARATUS FOR SERRATED CUTTING EDGESFiled Sept. 12, 1960 m M 3 m km W a w 2H 5/ Mum/w EJc/Si' United StatesPatent Ofiiice 3,015,239 Patented Jan. 2, 1962 3,615,239 SHARPENING ANDFILING APPARATUS FOR SERRATED CUTTING EDGES William F. Just, 3860 RegionAve., Robbinsdale, Minn. Filed Sept. 12, 196i}, Ser. No. 55,250 8Ciaims. (CI. 76-36) This invention relates to apparatus for use infiling serrated cutting edges and more particularly to apparatus for usein filing and sharpening the teeth of saws.

An object of this invention is to provide a novel saw filing apparatus,of simple and inexpensive construction, for use in filing saws.

Another object of this invention is to provide a novel and improved sawfiling apparatus including a file holder arranged and constructed tosupport a file in predetermined relation with respect to the teeth of asaw to permit ready and accurate filing and sharpening of the saw teeth.

A further object of this invention is to provide a novel and improvedsaw filing apparatus including the file holder having a plurality ofpairs of file-receiving apertures arranged to receive and support a filein a plurality of predetermined positions with respect to oppositelyangled teeth of saws to permit ready and accurate filing of difierenttypes of saw blades.

These and other objects and advantages of my invention will more fullyappear from the following description, made in conection with theaccompanying drawings, wherein like reference characters refer to thesame or similar parts throu hout the several views, and in which:

FIG. 1 is a top plan view of my invention with certain parts thereofbroken away for clarity and illustrated in the different position bydotted line configuration;

FIG. 2 is a side elevational view of my invention;

FIG. 3 is a cross-sectional view of my invention taken approximatelyalong line 33 of FIG. 1 and looking in the direction of the arrows;

FIG. 4 is an enlarged fragmentary longitudinal section approximatelyalong the center line of FIG. 2 of my invention illustrating details ofcertain parts thereof; and

FIG. 5 is a cross'sectional view taken approximately along line 5-5 ofFIG. 1 and looking in the direction of the arrows.

Referring now to the drawings, most specifically to FIG. 1, it will beseen that one embodiment of my saw filing apparatus, generallydesignated in its entirety by the reference numeral 1%, includes asubstantially U- shaped file holder 11, preferably constructed of arigid metallic material. This channel-shaped file holder 11 includes abight or web portion 12 having a pair of spaced-apart legs 13 and 14integrally therewith and depending therefrom.

i It will be noted that each of the legs 13 and 14 of the channel-shapedfile holder 11 is provided with a plurality of longitudinally spaced,triangular-shaped recesses or apertures as best seen in FIGS. 1 and 2.These apertures are arranged in opposed pairs, the pairs designated bythe reference numerals 15, 16, 17 and 18. Referring now to FIG. 2, itwill be seen that all of the apertures are of substantially identicalsize and shape but that the apertures comprising each pair arelongitudinally offset with respect to each other. Actually each pair ofapertures is adapted to receive the file therein as best seen in FIG. 1to correctly position the file with regard to teeth of the saw to befiled. It will also be noted that the pair of apertures 15 arelongitudinally offset oppositely of the pair of apertures 16 while thepair of apertures 17 are longitudinally offset oppositely from the pairof apertures 18. Actually the pairs of apertures 15 and 16 comprise aset of file receiving apertures for filing the oppositely angled teethof a conventional crosscut hand saw. The pairs of apertures 17 and 18comprise a set of file receiving aperturesfor use in positioning a filefor filing and sharpening the oppositely angled teeth of a conventionalrip saw.

In this connection, the leading or cutting edge of a rip saw moreclosely approaches the vertical than the teeth in a cross cut saw, whilethe trailing edge of the teeth in both the rip and the cross cut saw isdisposed at an angle with respect to the vertical. it will also be notedthat while the actual cutting edge of each tooth in both the rip andcross cut saw is disposed in parallel relation but oppositely beveledwith regard to the next adjacent tooth which permits the teeth to notonly shear but to remove the sheared material to thereby form the kerf.Because of the angulated relation or opposite beveling of each adjacenttooth, I have arranged the pairs of apertures into sets as pointed outabove.

Referring again to FIG. 2 it will be seen that a file P, which is oftriangular cross section configuration, will be positioned and wedgedinto the lowermost portions of each of the recesses or apertures whenthe file is disposed in seated relation therewith. In order to providethe proper seating and angulation of a file within a pair of apertures,each of the apertures comprising a pair are similarly oriented withrespect to each other while the other pair of a set is differentlyarranged with respect to its associated pair. In this connection it willbe noted that the pair of apertures 15 are defined in part by sides 15aand 15b against which the sides of the file F are abutted. However, thesides 15a and 15b each of the apertures comprising the pair 15 aresimilarly oriented but are slightly longitudinally offset with respectto each other. The orientation of the sides 15a and 15b of the pair ofapertures 15 may be referenced to the bight or web portion 12 of thefile holder and it will be noted that the sides 16a and 16b of each ofthe apertures comprising the pair 16 are oriented similarly with respectto each other but are oppositely or differently oriented with respect tothe sides 15a and 15b of the pair of apertures 15. Thus it will be seenthat the apertures comprising each pair are similarly oriented but areoffset longitudinally with respect to each other and are differentlyoriented with respect to the other pairs of that set or of a differentset.

In this connection it will be noted that the sides 17a and 17b whichdefine in part the apertures of the pair 17 are similarly oriented withrespect to each other but are differently oriented with respect to thesides 18a and 18b which define the apertures 18.

Means are provided for releasably retaining the file F in seatedrelation within pair of apertures and this file-retaining mechanism 19includes a substantially flat file-engaging member 26*, preferablyformed of metallic material and having a threaded board 20a formed atone end thereof. Referring now to FIG. 4 it will be seen that thisfile-retaining mechanism 19 is also provided with means for adjustablyurging the file-engaging member 20 into engagement with file F and thismeans includes an elongate threaded screw 21 having an enlarged head21a, the threaded shank of the screw threadedly engaging and extendingthrough the threaded bore Ztla of the file-engaging member 20. In usethe file retaining mechanism 19 is positioned between the legs orflanges 13 and 14 with one end thereof disposed in engagement with thebight portion 12. The screw 21 is rotated thus causing the opposite endof the file engaging member 20 to be moved downwardly away from thebight portion 12 into engagement with the file F to cause the latter tobe urged into wedged relation within the pair of apertures in which itis seated. The file engaging mem- 26 are of the conventional coil type.

ber 20 will also be wedged into fixed relation between the file and theweb 12 and this file-engaging member may be released from its wedgingrelation with respect to the file by merely rotating the screw element21 in opposite direction to cause the end having the threaded bore 20ato move towards the web or bight portion 12.

My saw apparatus also includes means for positioning the file holder 11adjacent the saw blade withthe file carried thereby being disposed incorrect position in respect to the depth of the saw teeth. To this end Ihave provided a pair of yieldable positioning members 22 positioned inopposite ends of the elongate file holder 11 and projecting laterallyfrom one side thereof. The file holder 11 is provided with an opening 23at each end and the leg 14 in the positioning member 22 has one endthereof positioned within this opening, the other end portion thereofprojecting laterally outwardly there from. These positioning members 22are preferably formed of stainless steel since softer material would besubject to wear when positioned against the points of the teeth. Thesepositioning members are adjustably and yieldably mounted on the fileholder and the file holder is provided with a pair of elongate screws24, each having an enlarged head 25, these screws extending throughopenings formed in the ends of the bight portion 12 as best seen inFIGS. 2 and 3. Each of these screws which is provided with a threadedshank also extends through an opening in its associated positioningmember 22 and is threadedly engaged at its lower end by nut 25. Sincethe positioning members 22 are free to move vertically of the screwshank, a resilient means 26 are provided for normally urging thepositioning member downwardly against the nut 25 and these springsActually the positioning members 22 will engage the upper points orsurfaces of the teeth to properly position the file in the recessdefined by adjacent teeth of the saw, as best seen in FIG. 2. In orderto adjust the apparatus for sharpening saws which may vary in the sizeand depth with regard to the saw teeth, the positioning members may bevertically adjusted by rotation of the screw to cause the nut to bemoved upwardly which in turn causes the positioning member to be movedupwardly towards the bight portion 12.

In use, my apparatus may be used for quickly and accurately sharpeningthe teeth of saws. If a conventional cross cut saw S is to be filed, afile F will be positioned within the apertures 15 as illustrated in fullline configuration in FIG. 1, to permit the cutting edge of every othertooth having this particular angulated bevel to be sharpened or filed.It should be pointed out however that prior to filing or sharpeningeither of the beveled surfaces of the teeth, the teeth should be fileddown or jointed whereby all the teeth have the same height. When thetops or points of the teeth are filed down so that the teeth have thesame height, these teeth will have a fiat reflective surface. When thefile is positioned in the apertures 15 the side of the file positionedagainst the side 1511 which defines the aperture 15 will be positionedagainst the leading or cutting edge of the cross cut teeth while theside of the file which is positioned against the side 1512 will bedisposed in engagement with the trailing edge of the next adjacenttooth. The file will be positioned at one end thereof extending betweenand engaged within the apertures 15 and projecting outwardly from theside of the file holder 11 as best seen in FIG. 1. The positioningmembers 22 will be positioned against the serrated teeth of the saw asbest seen in FIG. 2 and the saw filing apparatus will then be moved fromfull line position in FIG. 1 to the dotted line position in FIG. 1. Thisinitial positioning of the file with respect to the angle defined by thenotch between the adjacent teeth plus the proper angulation with respectto the beveled cutting surface is extremely imconnection the user willbe looking directly downwardly upon the teeth. During the initial stepof the filing op eration the dull or unsharpened apex of the teeth willreflect light. This reflective surface will be somewhat reduced by theinitial filing action as when the file is positioned within the pair ofapertures. During the second step, the operator merely watches thereflective surface until the reflective surface disappears and then theoperator will know that a point has been reached for that particulartooth. The next tooth Will be filed until the reflective surfacedisappears and in this manner all of the teeth will be sharpened andalso will be of substantially the same height to insure effectivecutting by the saw. In order to avoid unnecessary glare l have pro videda glare shield 27, formed of a transparent but tinted material such asPlexiglas or glass which is secured to the bight portion 12 of the fileholder 11 by means of the screws 24, the heads 25 of which clamp theglare shield 28 against the web portion.

It will therefore be seen from the preceding paragraphs that I haveprovided a filing saw apparatus which, while being of simple butinexpensive construction, permits a conventional hand saw of the crosscut or rip type to be readily and accurately filed. It will also be seenfrom the foregoing description that my novel saw filing apparatus is soarranged and constructed that a person unskilled in the operation offiling saws may readily and accurately file a saw. It will therefore beseen from the above description that I have provided a novel saw filingapparatus which permits saws to be filed in a more efficient manner thanany heretofore comparable structures.

What I claim is:

1. A saw filing apparatus for use in filing saws comprising an elongatechannel-shaped file holder including a bight portion having a pair ofspaced apart legs depending therefrom, a plurality of longitudinallyspaced, triangular-shaped apertures formed in each of said legs andbeing arranged in sets of opposed pairs, the apertures of each pairbeing of substantially identical shape and size and being slightlylongitudinally offset with respect to each other to permit an elongatefile of triangular cross-sectional shape to be positioned within a pairof said apertures with the longitudinal axis of the file being disposedin angulated relation with respect to the longitudinal axis of theelongate channel-shaped file holder, the apertures of one pair in one ofsaid sets being longitudinally offset oppositely of the other pair ofapertures in said one set whereby a file may be selectively positionedwithin each pair of apertures of each set for accurately sharpeningoppositely angled teeth of a saw, releasable retaining means cooperatingwith said apertures for retaining a file in snug-fitting relation withina pair of said apertures, and a pair of yieldable positioning memberspositioned at opposite ends of said elongate file holder and extendinglaterally from one leg thereof for engaging the uppermost surfaces ofthe saw teeth of a saw and cooperating with said apertures for correctlypositioning a file carried by said file holder in proper angulatedrelation with respect to the saw teeth.

2. The structure as defined in claim 1 wherein said positioning membersare vertically adjustable relative to said one leg. 7

3. The structure as defined in claim 1 wherein the apertures of one pairin said one set are oppositely oriented with respect to the apertures ofthe other pair in said one set.

4. A saw filing apparatus for use in filing saws com-- prising anelongate, substantially U-shapcd file holder including a substantiallyflat bight portion having a pair of legs depending therefrom, aplurality of longitudinally spaced, triangular-shaped apertures formedin each of said legs and being arranged in sets of opposed pairs, eachof said apertures being of substantially the same size and shape, theapertures of each pair being similarly oriented but longitudinallyoifset with respect to each other, the apertures of one pair in one ofsaid sets being longitudinally offset oppositely of the other pair ofapertures in said one set whereby a file may be selectively positionedwithin each pair of apertures of each set for accurately sharpeningoppositely angled teeth of a saw, an elongate retaining membercooperating with said apertures for releasably wedging a file downwardlyin snug-fitting relation within a pair of said apertures, and a pair ofyieldable positioning members carried by opposite ends of said fileholder and extending laterally from one leg thereof for engaging theuppermost surfaces of the sawteeth of a saw and cooperating with saidapertures for correctly positioning a file carried by said file holderin proper angulated relation with respect to the saw teeth.

5. The structure as defined in claim 4 wherein said retaining member isinterposed between the legs of said file holder and in angulatedrelation with said bight portion when said retaining member is inwedging relation with a file.

6. The structure as defined in claim 5 wherein the apertures of eachpair are similarly oriented with respect to each other and orienteddifierently with respect to the apertures of other of said pairs.

7. The structure as defined in claim 4 and a substantially transparentglare shield member secured to the bight portion of said file holder andextending laterally from one side thereof for facilitating inspection ofthe teeth of the saw.

8. A saw filing apparatus for use in filing saws comprising an elongatesubstantially U-shaped file holder including a bight portion having apair of legs depending therefrom, a plurality of longitudinally spacedtriangular-shaped apertures formed in each of said legs and beingarranged in said sets of opposed pairs, said apertures being ofsubstantially the same size and shape and the apertures of each pairbeing similarly oriented but longitudinally offset with respect to eachother, the apertures of one pair in one of said sets beinglongitudinally ofiset oppositely of the other pair of apertures in saidone set, an elongate file of substantially triangular cross sectionalconfiguration positioned in a pair of said apertures and projectinglaterally from one leg of said file holder in angulated relationtherewith, an elongate reraining member disposed between said leg and ininclined relation with bight portion and said file for wedging thelatter downwardly in snug fitting relation within said last mentionedpair of apertures, means for releasably retaining said retaining memberin wedging relation with the file, and a pair of yieldable positioningmembers carried by opposite ends of said file holder extending laterallyfrom one leg thereof for engaging the uppermost surfaces of the sawteeth and cooperating with said apertures for correctly positioning saidfile in proper angulated relation with respect to the sawteeth of a filewhen said apparatus is used for filing such a saw.

